// 兼容621px宽度以上的

    header {
        width: 100vw;
        height: 100vh;
        background-image: url("https://api.ixiaowai.cn/api/api.php");
        background-repeat: no-repeat;
        background-size: cover;
        background-position: top center;
        /*设置背景图片为顶部居中，用于兼容小尺寸设备体验*/
        // 开始定义导航栏样式
        >nav {
            width: 100vw;
            height: 65px;
            display: flex;
            // position: -webkit-sticky;
            // position: sticky;
            position: fixed;
            top: 0;
            left: 0;
            z-index: 9000;
            transition: 200ms;
            // border: 1px solid red;
            justify-content: center;
            align-items: center;
            background-color: rgba(0, 0, 0, 0.6);
            padding: 0px 6vw;
            h1 {
                margin-right: auto;
                font-size: 32px;
                color: white;
                cursor: pointer;
                transition: 400ms;
                &:hover {
                    color: gray;
                }
            }
            >ul {
                display: flex;
                height: 100%;
                list-style: none;
                >li {
                    display: flex;
                    justify-content: center;
                    align-items: center;
                    height: 100%;
                    padding: 0px 8px;
                    transition: 400ms;
                    transition-delay: 50ms;
                    &:hover {
                        background-color: white;
                    }
                    &:hover a {
                        color: black;
                        font-weight: 900;
                    }
                    &:hover i {
                        color: black;
                        font-weight: 900;
                    }
                    >i {
                        color: white;
                        margin-right: 5px;
                        transition: 400ms;
                        transition-delay: 50ms;
                    }
                    >a {
                        color: white;
                        transition: 400ms;
                        transition-delay: 50ms;
                        
                    }
                }
                
            }
            #header_nav_span {
                display: none;
            }
        }
        // 结束定义导航栏样式
        //开始定义头部内容区域
        div {
            width: 100vw;
            height: 100vh;
            position: absolute;
            top: 0;
            left: 0;
            padding: 0px 60px;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            background-color: rgba(0, 0, 0, 0.4);
            transition: 200ms;
            & *:nth-last-of-type(n+1) {
                margin-bottom: 35px;
            }
            & *:nth-last-of-type {
                margin: 0;
            }
            h2 {
                display: flex;
                color: white;
                font-size: 28px;
            }
            p {
                color: white;
                font-size: 18px;
                text-align: center;
            }
            a {
                color: white;
                padding: 8px 22px;
                text-align: center;
                background-color: #87CEEB;
                border-radius: 50px;
                font-size: 16px;
                transition: 400ms;
                &:hover {
                    background-color: white;
                    color: #87CEEB;
                }
            }
        }
    }
    // 结束定义头部内容区域
